ESTAN GmbH Schliengen



Liquid-cooled asynchronous motors

These motors are motor-casing cooled, i.e. they have a double-jacket. As a cooling medium, water or oil can be used. The cooling medium flows around the inner stator jacket. Due to such optimal cooling the motors achieve a significantly higher efficienca compared to motors with a surface ventilation.

The motors can be designed individually for various voltages and frequencies as well as for reverse operation. Standard version with integrated temperature sensor.


  • laboratory units
  • office machines
  • labelling machines
  • pumps


  • higher output in the same construction volume
  • no air turbulences by ventilation with fan blade
  • no noises by streaming air
  • the heat loss of the motor does not affect its immediate surrounding

Above mentioned benefits are most important for:

  • compact installation conditions without sufficient cooling possibility by air
  • high ambient temperatures
  • precision machines
  • in the vicinity of easily combustible materials

Nowadays more and more attention is paid on the freedom from noises at the workplace, which speaks for our liquid-cooled motors.


The motors have a cylindric jacket and are available in B14 as standard. Other mounting methods on request.

Versions with:

  • 1 or 2 shaft ends
  • hollow shaft
  • strengthened shaft ends
  • magnet or spring pressure brakes

Electric versions:
The motors can be designed for:

  • all general voltages and frequencies up to 500 Hz
  • especially for reverse operation
  • for short term operation
  • with built-in thermoprotection elements

Our motors are fitted with pluggable components instead of the usual connections in the terminal box.

Protection class:

IP 54


On request we supply static frequency converters adjusted to the motors.

Please see a PDF-file of the individual product brochure here:


Liquid-cooled asynchrom motors.pdf


Designed by Heinz Beilharz